Method of vulcanizing rubber soles to shoes



,(No Model.)

G. 1:". BUTTBRFIELD.

' METHOD 0F YULGANIZING RUBBER SOLES T0 SHOES'.

No. 574,239. 'Patented Dec; 29, 1896.V

WWI/W WITNEEEn- INVENTRL NITED STATES GEORGE F. BUTTERFIELD, OF STONEI'IAM, MASSACHUSETTS.

METHOD OF VULCANIZING RUBBER SOLES TO SHOES.

SPECIFICATION forming part of Letters Patent No. 574,239, dated December 29, 1896.

Application filed LT1-111e l, 1896. Serial No. 593,725. (No specimens.)

To all whom t nto/,y concern/.-

Be it known that I, GEORGE F. BUTTER- FIELD, of Stoneham, in the county of Middlesex and State of Massachusetts, haveinvented certain new and useful Improvements in the Method of Vulcanizin g RubberSoles to Shoes, of which the following, taken in connection with the accompanying drawings, is a specification.

This invention is an improved method of securing rubber soles permanently to the leather bottoms of boots and shoes.

VMy novel method contemplates the forma` tion of a sole or sole and heel of any suitable shape of vulcanized rubber or any desired compound thereof and of any proper degree of hardness, then coating the upper surface of suc-h sole with rubber-cement and applying thereon a sheet of unvulcanized-rubber compound, then coating the leather bottom of the lasted shoe with rubber-cement and placing it over and holding it rmly upon said unvulcaniz'ed sheet, and finally vulcanizin g such sheet and thereby firmly unit-ing said shoe and sole. Ground cork or mineral-wool may be compounded with the rubber, or the material in the interior of the sole and heel may be of the form known as sponge-rubber, having numerous small air-cavities in it, thus forming a sort of pneumatic sole.

The means illustrated for curing the interposed unvulcanized sheet include a closed steam-chamber upon which is placed the independent and removable mold-plate containing, in a recess in its upper surface, the vulcanized sole covered with the unvulcanized sheet, in combination with a frame and screws for holding the shoe and its last and the moldplate itself in position while said sheet is being sufficiently cured by the heat conducted to it. Such frame and screws are shown connected to the steam-chamber to resist the eX- pansion of the rubber, but the steam-pressure is controlled by the walls of the chamber.

In the drawings, Figure l is an elevation, partly in vertical section, showing my apparatus with a shoe held uponl the mold-plate to secure its rubber sole in place. Fig. 2 is an edge view of the mold-cap; and Fig. 3 an enlarged transverse section through the shoe at the dotted line 3, Fig. 1.

A represents the closed steam-chamber,having inlet and outlet pipes B.

C is the mold-plate, resting on the top of the chamber A between guides-ribs a.. This mold-plate has in its Lipper surface a soleand-hecl-shaped recess in which the rubber sole and heel are rst formed and vulcanized, the cap D (shown in Fig. 2) closing the top of the mold and being held down by the screws E E, which engage screw-threads in the frame F. Guide-pins G serve to locato the cap properly with relation to the moldplate, and fingers d on the cap engage by a sidewise movement with the terminal necks e on the screws to raise the cap when desired. Marginal plates I lit snugly around the sides of the shoe along the inseam. The frame F is held at each end to the chamber A by a stout rod f, one of which rods forms a pivot when the other is withdrawn. Thus the frame and its screws may be turned up when desired.

The steam in chamber A is at a high temperature and heats, by conduction, the moldplate C, so as to effectually cure the rubber in the mold. A series of these soles may be prepared in readiness for application to shoes, or, if preferred, each sole may be applied before its removal from the mold.

Vhen the sole and shoe are to be united, the vulcanized sole in the mold is coated on its upper surface with rubber-cement, and the leather bottom of the shoe is similarly coated.

Then a sheet of unvulcanized rubber H, of good quality, is applied over the top of the vulcanized sole and heel and the shoe-bottom fitted carefully and pressed iirmly thereon. The edges of the welt or of the sole, or both, project outwardly all around and are caught between the mold-plate C and the marginal plates 'L being pressed Very iirmly by the screws E E, so that the rubber is prevented from escaping around the margins of the mold. The screws J press down upon the lasted shoe and upon the head of the last, so,

as to hold the shoe most rmly. Steam is then admitted to the chamber A,an d the moldplate O and rubber therein are heated thereby,

the heat being maintained until the relatively 1 oo thin sheet of rubber I-I is sufficiently cured.

In vulcanizing rubber onto leather it isimportant to have the heat applied only on one side and direetlyto the rubber. In this Way the leather is not injured and the rubber is most irinly united to the leather. Suitable apparatus for this Work is also set forth in my application for patent thereon liled February '18, 1896, Serial No. 579,724.

I Claim as my invention- The described method of uniting vuleair ized-rubber soles to the leather bottoms of boots and shoes, consisting in forming such sole in a mold and suitably Vuleanizing it therein; then coating` the upper surface of such sole With rubbeneement and applying thereon u sheet of unvuleanized-rubbereo1npound; then coating' the shoe-bottoni with rubber-Cement and holding the shoe pressed firmly upon said unvuleanized sheet, and

iinally Vuleanizing` such sheet While the shoe- GEORGE F. lUTTERFIELD.

lVitnesses:

A. II. SPENCER, N. K. BAKER. 

